A variety of reasons may cause soreness and tenderness in the calves, among which may be gastrocnemius muscle strain caused by excessive exercise, micronutrient deficiencies, insufficient blood supply to the arteries of the lower extremities, and poor venous return to the lower extremities. 1. Gastrocnemius muscle strain: If the patient has carried out high-intensity leg strength exercise a few days ago, the gastrocnemius muscle will feel soreness and tenderness. Clinical manifestations are also soreness and weakness in the calf area. 2. Lack of trace elements: when the body lacks calcium, it is very likely that the calves will have weakness and tenderness. At the same time, there may also be intermittent cramps. 3. Insufficient blood supply to the arteries of the lower limbs and poor venous return to the lower limbs: if the arteries of the lower limbs are clogged or deformed, it can lead to their insufficient blood supply, and the calves will have the symptom of soreness and weakness; if the poor blood return is caused by the venous lesions of the lower limbs, there will be oedema of the lower limbs, and the calves will feel powerless and weak as well. In addition to the above reasons, neurological diseases and cervical spine diseases can cause patients to have sore and weak legs. Therefore, it is recommended that patients with weak and tender calves should consult a doctor in time, make a diagnosis in the hospital, clarify the exact condition corresponding to the symptoms, and carry out treatment according to the doctor’s instructions.